埋地管道外防腐层的检测与修复

防腐层性能的好坏直接影响到管道的使用寿命。而由于施工质量、自然老化等原因导致埋地管道防腐层破损的现象时有发生。因此,适时开展防腐层的检测与修复十分必要。在分析国内埋地管道防腐技术现状的基础上,介绍了目前常用的几种管道外防腐层检测技术和防腐层修复工艺,最后根据济淄线管道防腐层检测与修复的实践,提出了几点建议。     

ACVG、DCVG技术在输气管道外检测中的应用

外防腐层是埋地钢制管道控制腐蚀的重要部分,ACVG和DCVG是基于不同原理的两种外防腐层检测技术.文中通过对某在役管道ACVG、DCVG地面间接检测结果进行分析比较,并在直接开挖结果对上述两种检测结果验证的基础上,总结了ACVG和DCVG对外防腐层缺陷检测的不同优势,此两种检测方法配合使用可以大大提高外防腐层缺陷的检测...     

城市天然气管网外防腐层的选用

城市天然气钢管网外防腐层的选用，经历了不同的地质单元可选用不同的涂层材料。只有根据管道的运行条件，土壤状况，施工环境和工艺，管道设计寿命，环保要求以及经济合理性等各方面进行全面考虑，综合平衡，才能选出切合实际的防腐层材料。其主要因素是考虑技术可行性，即要考虑满足管道运行条件和施工工艺的要求，同时还应在施工环境允许的条件下，对防腐效果相同的各种涂层进行经济比较，从中选择满足技术性能要求而又经济的涂层。因此，技术可行性是防腐层选择的基本出发点，其他因素要服从这一前提的要求。     

SEBF熔融结合环氧粉末防腐层

叙述了钢套钢直埋蒸汽管道外防腐层选择的原则,对目前常用的3种防腐层性能进行了比较,在不同试验条件下,对SEBF耐温型熔融结合环氧粉末涂层电阻值、增重率、抗CI-应力腐蚀性能、抗腐蚀疲劳性能及耐温性能进行了试验验证。     

水平定向钻管道防腐层的选择和检验

文中从讨论管道防腐层的机械性能和检验方法出发,分析了水平定向钻管道防腐层的质量影响因子及常用防腐层机械性能对比试验,介绍了水平定向钻管道防腐层的抗磨损层选择方法和工程经验。研究表明,推荐采用环氧类涂层用于水平定向钻管道表面抗磨损。水平定向钻穿越后,利用管道阴极保护馈电试验和防腐层平均电导率可以有效评估穿越后防腐层的质量。     

PCM+在长输管道外防腐层检测中的应用

通过比较各种长输管道外防腐层检测技术,得出PCM+(多频管中电流法)的优越性,同时介绍了PCM+检测技术原理,详细分析了PCM+在长输管道外防腐层检测中破损点严重程度评定和定位技术,及在管道整体外防腐层等级综合评价中的应用,在实际检验中得出破损点性质判定规律及如何根据信号图来判断缺陷方法。文中得出一些规律有利于提高PCM+在长输管道外防腐层检测中的缺陷检测率和准确率。     

哈萨克斯坦第三油气处理厂厂外管道防腐设计

介绍了哈萨克斯坦第三油气处理厂厂外管道防腐工艺的选择,根据管线穿越土壤的介质和管线规格数量,选择了3PE外防腐层加阴极保护的联合保护方案,并提出了施工要求.投入运行后,效果良好.     

高纯氮气管道工程的施工技术

以北方气体产品公司的氮气管道工程为例，对输送高纯氮气的管道工程的施工工艺、技术进行了介绍，总结出此类管道应采用的施工工艺：内壁处理采用酸洗、磷化；外壁防腐采用3层PE外防腐加阴极保护的联合保护；管道焊接采用氩弧焊打底，手工焊填充罩面；管道安装后进行通球、吹扫；埋地管道的保护措施等。通过对工程实践过程介绍予以分析，证明此套方案是切实可行的，且经济可靠，为类似高纯气体管道的施工提供了参考。     

管道防腐涂层的现状与展望

管道的腐蚀问题是影响管道系统可靠性及使用寿命的关键因素,选择和使用合理的防腐涂层,对管道的安全运行、使用寿命及降低经济成本都具有十分重要的意义。文中简述了管道腐蚀产生的原因,综述了管道防腐涂层的发展概况,着重介绍了液态聚氨酯防腐涂料、无机非金属防腐层、纳米改性材料涂层等管道防腐涂层技术的新发展,提出了这些涂层在管道防腐应用中存在的问题,并对管道防腐涂层的发展前景做了展望。     

石油沥青防腐管道腐蚀特点及防护

介绍了石油沥青防腐管道的腐蚀特点,并在分析、总结埋地石油沥青防腐管道内检测、防腐层大修的基础上提出了防护对策,具有一定的借鉴作用。     

Analysis of factors affecting the choice of route of pedestrians

Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD).

An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip.

It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links.     

Non-parametric analyses of efficiency of airports

This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress.     

波纹管应力分析研究进展

评述了波纹管应力理论研究方法的进展情况，围绕解析法、工程近似法和数值法，对波纹管理论研究中的一些主要成果作了较详细的回顾和总结，对各种研究方法作出了评价，展望了亟待解决的一些问题。     

实现多组态计量软件集中监控的可行性分析

天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本.     

注汽管道承压能力评估和实物试验验证

基于失效评估图技术对某注汽管道进行了承压能力评价,给出了管线在不同腐蚀壁厚情况下的极限承压能力和极限裂纹尺寸。并利用实物爆破试验验证了评价方法的安全性和有效性,通过对爆破断口进行宏观和微观分析,发现管段的开裂属于脆性开裂。     

输油管道中原油乳状液的流变性研究

原油乳状液的流变性是原油开采后在管道中输送的重要研究方面,为了更好地研究这一性质,采用电动搅拌机、偏光显微镜以及流变仪等仪器来测定不同含水率的原油乳状液在不同条件下的黏度,观测不同含水率的原油乳状液在偏光显微镜下的形态。并且分别对原油乳状液的黏度与含水率之间的关系以及与剪切速率之间的关系进行研究,初步确定了所测区块原油乳状液的转相点以及该区块原油乳状液的流变特性,为生产中的油气集输提供了理论依据。     

埋地管道防腐保温层失效评价

明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。     

城市轨道交通杂散电流监测系统概述

介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。     

Preliminary results of an analysis of areas of influence in Shanghai

The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda.     

Direct analysis of the perceived importance of attributes of reliability of travel modes in urban travel

Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area.